The Administrative Order on Consent (AOC) requires the Navy and Defense Logistics Agency (DLA) to research and evaluate structural upgrades to the existing tanks at Red Hill. The tanks are constructed of concrete with quarter-inch steel plates forming a liner around the barrel and top of the tanks, and half-inch steel plates lining the bottom of the tanks. The concrete varies from 2 ½ to 4 feet thick, and the entire tank sits atop a concrete foundation that is 20 feet thick.
On September 9, 2019 the Navy and DLA submitted to EPA and Hawaii Department of Health a proposal to upgrade the large tanks at the facility. This proposal, available for viewing below, includes utilizing the existing physical structure of the single walled tanks and implementing numerous measures to improve various aspects of the underground tank system. Some limited information has been redacted due to federal regulations restricting the public disclosure of privileged information, such as estimated procurement costs and the location of some infrastructure. EPA and the Hawaii Department of Health are reviewing the proposal and public comments prior to issuing an approval or disapproval.
Tank Upgrade Alternatives and Release Detection Proposal (PDF)(102 pp, 5 MB,
September 9, 2019)
Navy and Defense Logistics Agency Tank Upgrade Alternatives Decision Document and Implementation Plan.